The present invention relates to a locking device for locking caps upon the necks of tanks, the primary use being for securing the caps of motor vehicle gas tanks in place to prevent the theft of fuel.
U.S. Pat. No. 3,756,047 issued Sept. 4, 1973 discloses a locking device consisting of a cylindrical body member having a cup-like form and terminating in a two-part inwardly extending collar. The device is designed so that the inwardly extending collar portion may bypass the tank cap as the device is installed or removed and yet be locked so as to prevent installation or removal. The two inwardly extending collar members are disposed in overlaying relationship and held together on one end by means of a rivet so as to render one collar member pivotally movable. The other collar member is permanently fastened into a recess of the body member. Both collar members have on their opposite or unriveted ends apertures which, when aligned in registration, permit passage therethrough of the shackle of a suitable locking mechanism. With the device in locked position upon the cap and about the filling neck of a tank, the shackle of the locking mechanism passes through the registering apertures and prevents the locked device from being removed by an unauthorized person.
In the patented locking device, the cup-like body member is held by the collar members more or less directly over and in alignment with the neck of the tank. In many motor vehicles, however, the neck of the gas tank extends into a cramped, highly restricted area only slightly larger than the minimum required to receive the tank cap. However, as the tank cap must be rotated when it is being affixed to the tank neck, there is usually room about at least three quarters of the tank cap for a hand, although the other quarter of the tank cap may be almost flush against the compartment wall when the tank cap is in place. While the pivotal member of the patented device includes a pair of apertures on the opposite or unriveted end, the effect of the pair of apertures is to enable the collar members to be snugly fit upon tank necks of different size and not for the effect of enabling the axis of the cup-like member to be displaced with respect to the axis of the tank neck or caps. If one utilized the aperture giving the collar members the loosest fit rather than the one giving them the tightest fit, the entire locking device would have fit loosely on the tank cap, thus promoting the chance of a spark being formed in an area where sparks are to be assiduously avoided, or, worse, been removable from the tank neck. Thus there remains the need for a locking device which can accommodate itself to the cramped compartments typically available about tank necks and caps.
Accordingly, it is an object of the present invention to provide a locking device wherein the cup-like body member may be seated upon a tank neck or cap with the cup-like body member being axially offset from the tank neck or cap.
Another object is to provide a simple, strong, safe and inexpensive locking device which is efficient, long lasting and easy to operate.